<!DOCTYPE html>
<html>
<head>
    <title></title>
    <script type="text/javascript" src="../js/jquery-1.8.3.min.js"></script>
</head>
<body>
<script>
    var a = 111;
    var A = function(){
        this.a = 1;
        var a = 11;
        var self = this;
        this.conf = function(){
            this.a = 2;
//            var self = this;
//            self.a = 2;
            alert(self.a);
            alert(this.a);
            alert(a);
            alert(window.a);
//            alert(self.a);
        }
    }

    var o = new A();
    o.conf();
</script>
</body>
</html>